Infusion of fluid components in rapid succession is required by a variety of medical and non-medical processes.
One example is the administration of the tachycardia drug adenosine. Adenosine is both an endogenous nucleoside and a drug that is commonly used as an antiarrhythmic agent and sometimes in cardiac diagnostic testing. Adenosine is typically employed in the form of a sterile, nonpyrogenic solution for intravenous injection. The drug adenosine possesses a half-life of less than 10 seconds and a duration of one to two minutes. Therefore, to achieve administration of active drug, adenosine often is delivered by rapid intravenous bolus over 1-2 seconds followed immediately by a rapid saline flush to aid in the injection reaching the subject's systemic circulation.
Traditional adenosine administration involves injecting the drug using a syringe, removing the empty adenosine syringe from the intravenous apparatus y-port, attaching a second, saline-filled syringe to the y-port, and then delivering the saline flush through the same port as the adenosine injection. Another conventional manner of adenosine administration includes employing a three-way stopcock and manipulating the stopcock valve in the intervening time between delivery of the medication and flush administration. The administration of adenosine often occurs in the emergency room context, where rapid and accurate completion of clinical protocols can be essential to the recovery of the patient.
Given the criticality of the speed of administration of adenosine to its effectiveness, there exists a need for methods and devices that alleviate the difficulty associated with the conventional process of adenosine administration. More generally, there exists a need for improved methods and devices for the administration other fluid agents that require rapid sequential delivery.
Other inventors have developed approaches to the problem by providing syringes and cartridges with a plurality of stoppers to allow sequential delivery of a therapeutic agent and a flush agent. See, e.g., U.S. Pat. Nos. 6,866,653, 5,899,881, 5,772,630, and 5,720,731. These devices and methods do not permit loading of the therapeutic agent and the flush agent through the same outlet through which the agents are delivered.